In this study, we investigated a phenomenon that one intuitively would assume does not exist: self-citations on the paper basis. Actually, papers citing themselves do exist in the Web of Science (WoS) database. In total, we obtained 44,857 papers that have self-citation relations in the WoS raw dataset. In part, they are database artefacts but in part they are due to papers citing themselves in the conclusion or appendix. We also found cases where paper self-citations occur due to publisher-made highlights promoting and citing the paper. We analyzed the self-citing papers according to selected metadata. We observed accumulations of the number of self-citing papers across publication years. We found a skewed distribution across countries, journals, authors, fields, and document types. Finally, we discuss the implications of paper self-citations for bibliometric indicators.

翻译：本研究探讨了一种直觉上被认为不存在的现象：基于论文层面的自引。实际上，在Web of Science（WoS）数据库中确实存在引用自身的论文。我们从WoS原始数据集中共获取了44,857篇具有自引关系的论文。其中部分属于数据库伪影，但另一部分源于论文在结论或附录中引用自身。我们还发现了因出版商制作的宣传亮点推广并引用该论文而导致的自引案例。我们根据选定的元数据对自引论文进行了分析。观察到自引论文数量随出版年份呈现累积趋势。发现其在国家、期刊、作者、学科领域和文献类型中均呈偏态分布。最后，我们讨论了论文自引对文献计量指标的影响。